Sensor integrated circuits are widely used in automobile control systems and other safety critical applications. Vehicle safety standards such as ISO 26262 and its Automotive Safety Integrity Level (ASIL) safety classification standard, set forth requirements related to permissible sensor quality levels, failure rates, and overall functional safety. One approach to meeting such mandates has been to use redundant identical circuits in a sensor integrated circuit.
In-phase current sensor integrated circuits used in motor control systems often implement redundancy using redundant signal processing channels such as a first main channel and a second diagnostic channel. During operation of the motor control system, output of the main channel is compared to output of the diagnostic channel to ensure that both outputs are similar. A failure in the main channel is detected by this comparison and communicated to the system controller of the motor control system. The system controller responds to the failure in any number of ways such as by permitting the motor control system to enter a safe state despite the failure.